10/23/2026
Do you know the signs of West Nile virus? 🦟
Most people infected with West Nile virus do not develop symptoms. However, about 1 in 5 people develop symptoms that can include fever, headache, body aches, joint pains, vomiting, diarrhea or rash.
While most symptoms are mild, in rare cases, West Nile virus can cause neuroinvasive disease, which affects the brain and nervous system and can lead to serious illness or death. People over age 60 and those with compromised immune systems are at greater risk for severe illness.
If you develop symptoms, contact your healthcare provider.
The best way to prevent West Nile virus is to protect yourself from mosquito bites. Use insect repellent, wear long sleeves and pants when possible, and drain standing water around your home.
For more information about West Nile virus, including prevention and mosquito activity in California, visit WestNile.ca.gov.